1. Field of the Invention
The present invention relates generally to packaging films capable of being heat-sealed closed during the packaging of a product and later peeled open by an end-user or consumer. More specifically, the films of the present invention comprise innovative blends of polybutylene and certain types of ionomers.
2. Discussion Of the Prior Art
A number of conventional packaging designs include heat-sealed packaging film which require the end-user to peel open the film, when initially removing a product from the package. In such packaging applications, the heat seal should ideally be strong enough to protect the product, but not so strong as to cause the end user undue difficulty in peeling open the package.
Broadly speaking, polybutylene polymers are known to be useful in preparing peelable heat seals. Furthermore, films have been commercialized comprising blends of about 3-4 wt parts polybutylene and 96-97 weight parts zinc neutralized acid copolymer of ethylene and methacrylic acid.
Generally speaking, ionomers are well known. Ionomers are derived from acid copolymers by wholly or partially neutralizing the acid moiety of the acid copolymer with a cation. Acid copolymers are well known and generally comprise an olefin monomer (such as ethylene) which is copolymerized with an acid comonomer (such as acrylic acid or methacrylic acid).
Applicant has discovered improved heat sealable compositions for peelable packaging applications, comprising innovative blends of polybutylene and certain types of ionomers.